Add admin setting to change max concurrent workers

api/graphql/resolvers/scanner.go

@@ -62,3 +62,25 @@ func (r *mutationResolver) SetPeriodicScanInterval(ctx context.Context, interval
 
 	return dbInterval, nil
 }
+
+func (r *mutationResolver) SetScannerConcurrentWorkers(ctx context.Context, workers int) (int, error) {
+	if workers < 0 {
+		return 0, errors.New("concurrent workers must be positive")
+	}
+
+	_, err := r.Database.Exec("UPDATE site_info SET concurrent_workers = ?", workers)
+	if err != nil {
+		return 0, err
+	}
+
+	var dbWorkers int
+
+	row := r.Database.QueryRow("SELECT concurrent_workers FROM site_info")
+	if err = row.Scan(&dbWorkers); err != nil {
+		return 0, err
+	}
+
+	scanner.ChangeScannerConcurrentWorkers(dbWorkers)
+
+	return dbWorkers, nil
+}